<p>Provided is a compressing device including a compressor with a compressing unit compressing a gas and a heat exchanger, the heat exchanger including: a cooling unit that cools a gas compressed by the compressing unit; a connection path that connects the compressing unit to the cooling unit; and a connection path branch portion that is branched from a part of the connection path. The connection path branch portion includes an attachment portion that is provided in a surface different from a surface facing the compressor in the heat exchanger. An instrumentation device is directly and strongly attached to the attachment portion.</p>